Royal Purple 10W-30 4984 Miles Subaru WRX

[edhackett]

Here's a UOA on Royal Purple 10W-30 with ~5K miles in a WRX. The analysis was done by BlackStone. The first number is for the virgin oil.

2003 Subaru WRX (2.0L Turbo)
10054 miles total on Car
4984 miles on oil
No make-up added (~1/3 quart used)
Oil in use from 2/8/03-6/3/03
Factory paper air filter
Pure One oil filter

code:

---

Al 0 - 4

Cr 0 - 1

Fe 0 - 6

Cu 0 - 4

Pb 0 - 2

Sn 0 - 1

Mo 107 - 104

Ni 0 - 0

Mn 0 - 0

Ag 0 - 0

Ti 0 - 0

K 0 - 0

B 0 - 0

Si 1 - 7

Ca 1736 - 1782

Mg 5 - 5

P 788 - 804

Zn 982 - 974

Ba 0 - 0



Viscosity SUS 210 60.5 - 56.5

Flash 445 F - 415 F

TBN 9.5 - 5.5

Fuel x -
Antifreeze x - 0.0

Water
Insoluables 0.0 - 0.5

---

The oil did shear from a very low 30W to a high 20W, a 6.6% loss. I monitored the oil pressure throughout the period, and there was no change, 27 psi idle, 82 psi at 3000 rpm with the oil at 180 F. As far as oil pressure was concerned, the car didn't show any indication of the oil thinning, and I can live with those wear numbers!

Ed Hackett

[ June 12, 2003, 07:29 AM: Message edited by: BOBISTHEOILGUY ]

 

[nicrfe1370]

First of all Ed, welcome to the forums, and way to get off to a running start by posting a UOA and a VOA.

If you've looked around at other Royal Purple results, you'll see it has taken some abuse. As far as wear numbers go, you had excellent results! The ease by which RP shears is a little disconcerting, and you seem to be at the limit of insolubles, but everything else is really spot-on.

If you want to compare your results with other Subarus, check for other posts of mine in this section, I have a spreadsheet with lots of Subaru UOA's.

 

[Patman]

Is this THE Ed Hackett? The one who made up that big oil article, More than you ever want to know about motor oil, comparing many oils many years ago? It was one of the first things I read on the net when I first got online in 1996! Very informative!!

Sorry to see yet another RP sample thinning out. Try Schaeffer Oil, Amsoil or Redline next time and I bet this doesn't happen.

[ June 12, 2003, 05:31 AM: Message edited by: Patman ]

 

[radiometer]

Can someone explain to me how this oil after being used has increased in CA and P? Actually, I had already noticed that after being used the UOA will show an increase of some of the additives. I have been somewhat puzzled about this.
As always, thank you.

 

[TooSlick]

There is some test to test variation in the levels of additives. It really isn't that much of an issue.

Wear numbers look fine in this case, and you could even run this oil a bit longer. One of the better RP analyses I've seen.

TooSlick

 

[Al]

I'm glad we see another RP analysis. Silicon low-and the numbers indicate that the engine is doing well. The shearing is a little troublingbut not a big deal. We would need to assume at this point that this oil cannot go extended drain intervals in this particular vehicle.

But still-nice report.

Thanks for posting

 

[Pablo]

GREAT REPORT for a turbo

I'd rather have my turbo shearing my oil down a bit at the end of an OCI (as mine does at 10K miles) than coking up half way (which I have seen when people take "cheap" oils to 5K+ in turbos!

Anyhow - you have a clean engine. Keep it up.

 

[Patman]

In my hasty reply earlier, I forgot to mention that despite the thinning out (which I still feel is not a good trait for an oil) that this oil protected this engine very well! Those wear numbers are simply awesome for a hard driven car.

At the same time, before I go singing the praises of Royal Purple, keep in mind that the WRX is very easy on it's oil, we've seen tons of very good oil reports from these engines.

I'm still anxious to see my wife's UOA on Royal Purple 5w30 at the end of this year. She should hit the 5000 mile mark around October or November. It'll be a good comparison to the 5000 mile interval I ran last year on Trisynthetic Mobil 1, which was also run from April to November. Same weather, same driving conditions, two different oils. Which one will win? Stay tuned!

 

[edhackett]

Patman: Yes, that'me. I wrote the original article in 1991. I was dissapointed to see the thinning also, but the wear numbers are all that matter in the end.

krholm: If there is oil loss due to vaporization, the non volatile additives will become concentrated in the oil. There is also the reality of analysis. Any numbers that are within 5% of each other can be considered the same value.

Pablo: I agree about the shearing. I'd much rather see an oil show a "normal" amount of shear, rather than being being thickened by oxidation or volatility.

Drstressor: The high insoluables could come from two main areas on the WRX. First would be coking in the turbo, which is unlikely as it is water cooled and is designed to thermosiphon coolant through the turbo after shutdown. Second would be blow-by from the combusion chamber. This is likely the cause, as at full boost the effective compression ratio is just under 16:1 and the computer richens the mixture to I _think_ the 10:1 range, anyway it does go quite rich at full throttle by design. There was no indication of fuel in the UOA.

Patman: The WRX does appear not to be handicapped by poor engineering and/or questionable metallurgy.

Ed

 

[nicrfe1370]

quote:

---

Originally posted by edhackett:
Patman: The WRX does appear not to be handicapped by poor engineering and/or questionable metallurgy.

---

That is a much more classy way to say what I believe than I could ever come up with.

 

[Drstressor]

Ed -- Your post indicates 0.5% fuel and a reduced flash point.

 

[Drstressor]

Some of the visosity drop and high insolubles could be the result of fuel contamination. Any indication why you might be running rich?

 

[Patman]

Good point, that 0.5% would thin out the oil. By how much I wonder though?

 

[Drstressor]

I only bring this up because I see the same thing (high particulates, some fuel dilution, depressed flash point) in my normally aspirated Honda during the winter. I never could understand how particulates could be high when the oil shows normal oxidation values. Maybe the particulates come from blowby during warmup when the fueling is rich as Ed suggests. Incompletely burned fuel rather than oxidize fuel could be the answer.

 

[Bror Jace]

Patman: "keep in mind that the WRX is very easy on it's oil, we've seen tons of very good oil reports from these engines."

I was thinking the same thing.

We saw one maybe a month ago ... maybe less. Either M1 or Amsoil, I think. Lengthy interval, very little wear.

EdHackett, I'm another one who liked your oft-referenced article and read it/looked it over numerous times. Having said that, I had to point out to everyone I talked to on the net for the past 3+ years that it was out of date and the brand specs had probably changed several times since then. The SAE classifications you cited in it gave it away for those who cared to read closely.

--- Bror Jace

 

[Mystic]

Ed Hackett, that article you wrote on oil additives was one of the best I ever read on the internet. It was excellent. I used to be interested in every oil supplement that came along and I would try one if there seemed to be enough good information that it worked or if a major oil company came out with a supplement (like Valvoiline did, for example). Your article helped to get me thinking differently.

When I heard of Royal Purple Motor Oil I was interested and thought about trying it, but I never did. So far this motor oil seemes to have not faired too well in VOA and UOA at this site, but then again there has not been too much VOA and UOA on it, either.

I have used Auto-RX, Neutra, and Schaeffer's #132. What are your ideas about these oil additives, Ed?

 

[edhackett]

It looks like my < symbols got mangled in the original post. The fuel value given on the UOA is less than 0.5.

The original article was written pre web and was first posted to rec.motorcycles. I had to run around to all of the distributors in town and call the oil companies to get the data. Now when I receive inquiries, I tell them to read the text and look up the current data for the oils they are interested in on the web.

Ed

 

[Dominic]

Oh wow, Ed Hackett

Nice oil report too, the TBN appears a little low and it sheared some... but at 5,000 miles it seems to have weared well.

Looks like you changed it at the right time!

 

[Bror Jace]

"The original article was written pre web and was first posted to rec.motorcycles. I had to run around to all of the distributors in town and call the oil companies to get the data. Now when I receive inquiries, I tell them to read the text and look up the current data for the oils they are interested in on the web."

I actually tried to do this using only on-line information about three years ago but the disparity and incompleteness of the data from the different manufactuers told me I was chasing a snipe.

Doesn't matter, even if it was complete at the time, it would be obsolete now. Look at all the companies now using molybdenum as a barrier anti-wear additive ... and the switch from SJ to SL changed most base oils.

Anyway, how do you feel about this brand of oil tested? Gonna continue to use it despite the shearing? Think the shearing was by design to improve power and maybe even fuel economy ... i.e., get people to use a thinner oil than they would otherwise choose?

--- Bror Jace

 

[edhackett]

Mystic: I haven't followed oil additives at all. I consider them to be bandaids at best and a complete waste of money at worst. However, from what I have seen of Auto-Rx, Neutra, and the Shaeffer's, they appear to be the real deal. I'm thinking of trying the Auto-Rx in my '90 GMC truck.

Dominic: I figure 5000 miles is an extended drain for a turbo. It looks like it might go to 7500, but I don't feel the need to push it.

Bror: Yes, I'm going to continue to use the oil for at least a full year to see how it does. The current interval will take me through the hotest part of the year and will be the most telling.

I think the shearing is normal. All oils shear to some extent. Some companies are just better at balancing the oxidation rate to the shear rate.

I'm not too concerned as this is a synthetic, which should still be delivering a film strength of a 30 or even 40 weight petroleum oil. Add that to what appears to be a top notch additive package and the amount of shear seen in my case is not really an issue.

Royal Purple sent me info on their oils some time ago. I thought it looked like a good product (OK, the logo and name are a bit hard to get past), but didn't have a local supply. The purchase of the WRX gave me chance to evaluate what oil might be a good match for at least 5000 mile changes. The independent studies confirming RP's claims convinced me to give it a try.

Ed